Because before Piccolo blew up the moon, it originally had a blue tint to it as shown here:

So he could change into a monkey, Vegeta created a new, artifical moon. Since he hastily made it in the heat of the moment or whatever, he decided to make it gray and black. That's why the moon is this way and we unfortunately, have no photos of the blue tinted moon we previously had.

I suspect this is a troll thread, but it's amusing and just in case someone really doesn't get it. Below is a photo of an "earth rise" shot while in orbit around the moon. [http://en.wikipedia.org/wiki/Earthrise]

Taken by Apollo 8 crewmember Bill Anders on December 24, 1968, showing the Earth seemingly rising above the lunar surface. Note that this phenomenon is only visible from someone in orbit around the Moon. Because of the Moon's synchronous rotation about the Earth (i.e., the same side of the Moon is always facing the Earth), no Earthrise can be observed by a stationary observer on the surface of the Moon.

Ok...so, from the photograph, the Earth is clearly in color which would mean the surface of the moon is also "in color" (e.g., same photograph). Could it have been enhanced and the color added later? It could have, but it wasn't. They took color film with them.

Week of Aug. 8, 1968
NASA releases color photographs from the first moon landing, while scientists pore over moon rocks with microscopes, spectroscopes and radiation counters.

Here, we see a shot from the moon. It's a color image. Which means, the moon's surface is also in color. Was it enhanced? No. Again, they took color film with them. Yes, it's the late 60s. Yes, they transmitted black & white video signals of them walking around, golfing, and driving their "buggy", but they also took color film that they then developed when returning to earth. Since they didn't have to worry about "beaming" back every photo back to earth.

BTW... there are 12 Hasselblad cameras on the moon that were left behind between 1969 and 1972. They left them so that they could bring back moon rocks instead.

So, there you have it. Now if you toss on the fact that the moon appears "white" most of the time and it's matted against space which appears "mostly black" most of the time, you have a bunch of color moon pictures that look "black & white". But don't forget the harvest moon. [http://en.wikipedia.org/wiki/Harvest_Moon]

Often, the Harvest Moon seems to be bigger or brighter or more colorful than other full moons. The warm color of the Moon shortly after it rises is caused by light from the Moon passing through a greater amount of atmospheric particles than when the moon is overhead.

The atmosphere preferentially scatters the bluish component of moonlight, which is really reflected white light from the sun, while allowing more of the reddish component of the light to pass though to one's eyes. Hence all celestial bodies look reddish when they are low in the sky.